Finding the Fourth Proportional to 1,038.34, 1,434.81 and 987.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,038.34 : 1,434.81 = 987.72 : x
2. Step 2: Convert to fraction form
   1,038.34/1,434.81 = 987.72/x
3. Step 3: Cross multiply
   1,038.34x = 1,434.81 × 987.72
4. Step 4: Simplify right side
   1,038.34x = 1,417,190.53
5. Step 5: Solve for x
   x = 1,417,190.53/1,038.34
6. Step 6: Final answer
   x = 1,364.86